高温力学试验装置的位移误差分析

Displacement Error Analysis of High Temperature Mechanical Testing Apparatus

耐高温材料用于航空航天领域,材料变形产生的位移是其性能中的一个关键参数,如何准确地测量这个位移仍为有待解决的问题和挑战。对高温力学试验装置进行设计,采用LVDT位移传感器间接测量材料的位移并提出了应变测量的修正算法。为了解决LVDT测量杆轴线与位移转换板的偏角引起的位移测量不准确问题,对二者的偏角进行计算并修正;为了解决间接测量方法引起的应变测量偏大问题,对连接件的变形进行修正,并对试件加载段和过渡段的变形进行修正。结果表明,LVDT测量的实际位移与理论位移的关系为L2=L1/cosα;应变修正后的杨氏模量与装置所测杨氏模量的关系为E1=2.112E2。

High-temperature resistant materials are used in aerospace application,the displacement caused by material deformation is a key parameter in its performance,how to measure this displacement accurately is still a problem and challenge.A high temperature mechanical testing apparatus was designed,a pair of LVDT displacement sensors was used to measure the material displacement indirectly and a correction algorithm of strain measurement was proposed.In order to solve the problem of inaccurate displacement measurement caused by the deflection angle of LVDT measurement rod axis and displacement conversion board,the deflection angle of both was calculated and corrected.In order to solve the problem of larger strain measurement caused by indirect measurement method,the deformation of the connectors was corrected,and the deformation of the loading section and the transition section was corrected.The results show that the relationship between the actual displacement and theoretical measured by LVDT is L2=L1/cosα.The relationship between Young′s Modulus after strain correction and Young′s Modulus measured by apparatus is E1=2.112E2.